Cathode ray tube faceplate having diverse optical means therein

ABSTRACT

A cathode ray tube having a faceplate panel wherein at least one optical insert of low-attenuation optical material is disposed through the faceplate in substantially the peripheral region thereof to provide at least one defined light channel therethrough. The insert, being covered by the peripheral portion of the screen, provides means for channeling a discrete portion of excited screen luminescence through the faceplate.

United States Patent Johnson 1 June6,1972

[54] CATHODE RAY TUBE FACEPLATE HAVING DIVERSE OPTICAL NIEANS THEREIN [72] Inventor: Alfred D. Johnson, Seneca Falls, N .Y.

{ 73] Assignee: Sylvania Electric Products Inc.

[22] Filed: May 4, 1970 [21] Appl. No.: 34,023

[52] U.S.Cl. ..313/92 R, 178/7.85, 178/6,

[51] Int. Cl ..Hlj 29/10,'H01j 29/89,H01j /16 [58] Field of Search ..313/92 LP, 65 LF; 178/6 [56] I References Cited UNITED STATES PATENTS 2,825,260 3/1958 OBrien ..350/96 2,983,835 5/1961 Frey ....313/89 2,999,163 9/1961 Beesem, ..i250/86 3,267,209 8/1966 Nagamori et a1. l 78/5.4

2,091,152 8/1937 Malpica ...'.313/92 LF X 3,027,219 3/1962 Bradley ..313/92 LF X 3,303,374 2/1967 Fyler ..313/92 LF 3,141,105 7/1964 Courtney-Pratt.... .313/92 LF X 3,210,597 10/1965 Siegmund et a1. ..178/6 3,474,445 10/1969 Redman ..313/92 LF X OTHER PUBLICATIONS Stuckert, IBM Technical Disclosure Bulletin; Vol. 4, No. 10, March, 1962, p. 47.

Gafiney, IBM Technical Disclosure Bulletin; Vol. No. 10; No. 12, May, 1968; page 1917.

Primary Examiner-Robert Segal Attorney-Norman J. O'Malley, Donald R. Castle and Frederick H. Rinn ABSTRACT 3 Claims, 3 Drawing Figures P'ATENTEDJUH 6 I912 SEN8SOR CONVERTER INVENTOR. ALFRED D. JOHNSON ATTORNEY BACKGROUND OF THE INVENTION This invention relates to a cathode ray tube and more particularly to a cathode ray tubefaceplate having discrete means therein for channeling a defined area of screen luminescence therethrough.

Certain types of cathode ray tube display devices utilized for the presentation of operational data and surveillance information have need for special tube related signalling to optimize intended operation of the device. For example, discrete signalling emanating within the tube has been particularly useful in effecting efficient operation of display devices in movable equipment such as aircraft and mobile vehicular installations. It has been found that during maneuvering, extraneous magnetic fields are often encountered that deleteriously afi'ect desired orientation of the required display pattern or raster. Since it is desirous to maintain display centering on the screen, various attempts have been made to provide display centering. One remedial attempt has been to embed a plurality of sensor conductors in the peripheral region of the faceplate beyond the normal scan area to pick-up the electron beam when the display raster is shifted off-center. Electron signalling thus received activates an automatic scan centering device to substantially restore the required display area to center. To fabricate a tube for this system is both costly and difficult.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of the invention to reduce the aforementioned disadvantages and to provide a cathode ray tube that has provisions therein to facilitate the use of optical signalling emanating from the excited screen thereof.

The foregoing objectsare achieved in one aspect of the invention by providing a cathode ray tube having a faceplate panel wherein at least one discrete optical insert, of low-attenuation optical material, having optical characteristics differing from those of the faceplate, is disposed in a compatibly formed aperture in substantially the peripheral region of the faceplate to provide at least one specialized light channel therethrough. The interior surface of the insert is fully covered by the peripheral portion of the cathodoluminescent screen to provide discrete channeling of excited luminescence of the specific overlying screen area to a definite area of the exterior surface of the faceplate. The defined optical signalling thus provided is utilized in a manner to optimize operational efficiency of the display device.

BRIEF DESCRIPTION OFITHE DRAWINGS HO. 1 is a sectional view of a cathode ray tube utilizing the invention;

FIG. 2 is a plan view of the faceplate portion taken along the line 2-2 of FIG. 1; and

FIG. 3 is a sectional view of a display assembly employing the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT For a better understanding of the present invention together with other and further objects, advantages and capabilities thereof, reference is made to the following specification and appended claims in connection with the aforedescribed drawmg.

With reference to the Figures, there is shown in FIG. 1 a cathode ray tube 11 whereof the envelope 13 comprises a panel portion 15, a funnel portion 17 and a neck portion 19. A cathodoluminescent screen 21 is formed on the interior surface 23 of the panel portion 15, and at least one electron gun 25 is positioned within the neck portion 19 in a manner to project an electron beam 27 to impinge the screen and excite the phosphor therein to a state of luminescence. The electron beam 27 is caused to scan the screen 21 by means not shown, which may be either electrostatic or electromagnetic, to effect a desired display raster 31, having, for example, a height a and a width b. While a substantially rectangular display raster 31 is shown, the disclosure is not intended to be limited thereto.

In referring particularly to the panel structure of the tube 11, the faceplate or panel portion 15 is formed of a substantially transparent glass of the type or types normally used for viewing panel construction. In substantially the peripheral region of the faceplate 15, there is at least one discrete optical insert 33 of low-attenuation optical material, such as, optical glass or a compaction of parallel optical fibers, having a height h substantially equalling the thickness of the panel 15. While the insert can be of substantially cylindrical form fitted into a substantially mating cylindrical aperture in the faceplate 15, it

has been found that an insert 33 contoured substantially as a technique, such as for example by utilizing a substantially opaque glass sealing frit 41, to form a hermetic seal therebetween. ln addition to the sealing function, the frit 41 provides a substantially opaque encompassing barrier shielding the optical insert 33 from refracted light in the contiguous faceplate material. This is particularly advantageous when an optical glass insert is employed. The smaller end surface 37 of the frustum-shaped insert 33 is polished and oriented substantially flush with the interior surface 23 of the faceplate 15, accordingly the larger end surface 35 of the insert is similarly polished and substantially flush with the faceplate exterior surface 43. It has been found that this wedge-type relationship is highly beneficial as it utilizes the force of the exterior ambient air pressure which pushes inwardly against the outer surface 35 of the insert thereby strengthening the hermetic jointure of the insert 33 in the panel faceplate 15.

As shown, the optical insert 33 is formed, for example, of a plurality of substantially parallel optical fibers 45 oriented substantially normal to the plane of the panel faceplate 15. Fiber optics material is an appropriate means because of its low attenuation and directional optical characteristics. Thus, the insert provides an efficient optical-pipe between the interior and exterior surfaces 23 and 43 of the envelope faceplate 15.

The location of the insert 33, being substantially peripherally disposed in the faceplate, as illustrated in FIGS. 1 and 2, is in an area covered by the screen 21 but in the region thereof preferably beyond the viewable display raster 31. The insert orientation is referenced from the faceplate axis 16 by the dimension d. While one insert 33 is shown, a plurality may be utilized in spaced apart relationship. For example, additional depositions of inserts at points47, 49, and 51, or at other appropriate locations in the areas adjacent thereto, in the faceplate 15 places an insert in adjacent relationship with each of the respective lateral dimensions 53, 54, 55, 56 of the raster 31 With reference to FIG. 3, there is shown a cathode ray tube display assembly 59 which utilizes the aforedesciibed tube 11 as the display medium therein. A bezel-type framing structure 61 is formed to substantially encircle the display panel portion 15 of the tube and is afiixed thereto, as for example, by a suitable adhesive 62. The frame 61 has a substantially instanding portion 63 with the leading edge 65 thereof defining the viewable portion of the panel 15. The location of the leading edge 65 is referenced from the panel axis 16 by the dimension f which is of a dimensional value less than the insert orientation dimension d. Thus, the instanding portion 63 of the frame covers the insert location/locations. Within the framing structure 61, there is positioned at least one fiber optics conduit 67 whereof the receptive end 69 is affixed in a manner to be contiguous with the insert exterior surface 35. The conduit 67 extends exteriorly from the framing structure 61 to conversion sensing means 71 wherein discrete optical energy conducted from the screen is converted to signalling which is by electrical conductive means 73 transferred to circuitry not shown and utilized to optimize operational efficiency of the tube 11. Operationally, as the display raster 31 may be moved offcenter from axis 16, by external influences, the electron beam 27 excites that part of the screen overlying one of the optical inserts, such as' for example insert 33. The defined light emanating therefrom traverses the insert and is conducted to the sensor-converter 71 by the conduit 67 wherein corrective signalling is initiated to shift the display back to desired positioning on the display panel. Being peripherally oriented in the faceplate l5 and hidden by the framing structure 61, the inserts are unobtrusive to the image display on the panel 15.

While the foregoing description relates primarily to a tube constructed to effect automatic scan centering, it is within the scope of the invention to include other insert orientations and usages. For example, one or more inserts can be located in the peripheral portion of the regular display raster area to receive a pulse of light as the raster is scanned. Such discrete pulses of optical energy can be converted to monitoring or signalling applications in the circuitry associated with the device.

Thus, there is provided an envelope for a cathode ray tube having discrete optical conductive means in the faceplate portion to effect expeditious channeling of defined areas of screen luminescence therethrough.

While there have been shown and described what are at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention as defined by the appended claims.

I claim:

1. In a cathode ray tube having at least one electron gun oriented therein to project at least one electron beam to a related cathodoluminescent screen to provide a display raster thereon, a panel structure comprising: a glass faceplate portion having said screen disposed on the interior surface thereof, said said raster area; and a discrete optical insert formed of a plurality of substantially parallel optical fibers of low-attenuation optical material substantially shaped as a conical frustum and hermetically sealed in a compatible aperture in substantially the peripheral region of said faceplate outside of the normal display raster area but adjacent thereto to provide at least faces of said insert being substantially circular shaped with the smaller end surface of said frustum being substantially flush with the interior surface of said faceplate, and with the larger end surface thereof being substantially flush with the exterior surface of said faceplate, said interior surface of said insert being fully covered by the peripheral portion of said screen, said optical insert having optical characteristics differing from those of said faceplate to provide means for discretely channeling the excited luminescence of the specific overlying screen area to adefinite area of the exterior surface of said faceplate.

2. A cathode ray tube envelope according to claim 1 wherein said optical insert is formed of a plurality of parallel optical fibers oriented substantially normal to the plane of said faceplate portion. 7

3. A cathode ray tube panel structure according to claim I wherein said optical insert has polished interior and exterior surfaces.

screen area being larger than 

1. In a cathode ray tube having at least one electron gun oriented therein to project at least one electron beam to a related cathodoluminescent screen to provide a display raster thereon, a panel structure comprising: a glass faceplate portion having said screen disposed on the interior surface thereof, said screen area being larger than said raster area; and a discrete optical insert formed of a plurality of substantially parallel optical fibers of low-attenuation optical material substantially shaped as a conical frustum and hermetiCally sealed in a compatible aperture in substantially the peripheral region of said faceplate outside of the normal display raster area but adjacent thereto to provide at least one specialized light channel therethrough, said insert sealing material providing an opaque encompassing barrier shielding said insert from refracted light in said contiguous faceplate portion, the interior and exterior surfaces of said insert being substantially circular shaped with the smaller end surface of said frustum being substantially flush with the interior surface of said faceplate, and with the larger end surface thereof being substantially flush with the exterior surface of said faceplate, said interior surface of said insert being fully covered by the peripheral portion of said screen, said optical insert having optical characteristics differing from those of said faceplate to provide means for discretely channeling the excited luminescence of the specific overlying screen area to a definite area of the exterior surface of said faceplate.
 2. A cathode ray tube envelope according to claim 1 wherein said optical insert is formed of a plurality of parallel optical fibers oriented substantially normal to the plane of said faceplate portion.
 3. A cathode ray tube panel structure according to claim 1 wherein said optical insert has polished interior and exterior surfaces. 